The present invention relates to a gasket seal for a mass spectrometer.
It is known to use one or more O-rings to form an air tight or vacuum tight seal between two components of a mass spectrometer. The O-rings are manufactured from VITON® or another similar elastomer material. In particular, it is known to utilise an O-ring seal with a mass spectrometer where a pressure differential needs to be maintained e.g. between two vacuum chambers or between a vacuum chamber and the atmosphere.
It is known to utilise multiple separate O-ring seals in order provide multiple gas seals between two components of a mass spectrometer. For example, two or more O-rings may be provided between two mating surfaces of a mass spectrometer wherein each O-ring seals a separate specific region.
It will be understood by those skilled in the art that with conventional arrangements it is necessary to locate each O-ring seal separately and also to ensure that each O-ring seal has its own seating profile.
Many conventional mass spectrometers have complex sealing arrangements which utilise multiple O-ring seals, each of which need to be positioned carefully. The O-ring seals may also be subject to different tolerances. It is problematic to ensure that multiple O-ring seals are properly located.
Another problem with known mass spectrometers is that each location where an O-ring is to be provided requires careful dimension control in order to ensure that each O-ring will provide, in use, a gas or vacuum tight seal under compression. It will be appreciated by those skilled in the art that this can be difficult since different seal locations may have different tolerances and may be subjected to different temperature and pressure variations.
Another problem with known arrangements is that any variation across multiple seals can result in the lifting off of some of the seals or regions of reduced compression being formed. This can lead to leaks (in effect some seals can hold off nearby seals) which can also be difficult to locate.
It will be apparent that conventional mass spectrometers which incorporate multiple O-ring seals in close proximity to each other often involve complex designs which are complex to manufacture and assemble. An O-ring seal may also be prone to failure if a neighbouring O-ring seal is positioned incorrectly.
The complexity of using multiple O-ring seals and ensuring that each of the O-rings is positioned correctly and provides the correct seal under compression results in increased manufacturing costs. Conventional mass spectrometers incorporating multiple O-ring seals are also relatively complex and time consuming to service.
Another problem with locating multiple O-ring seals in close proximity to each other is that there is an increased risk of one (or more) of the O-ring seals being missed out during assembly of the mass spectrometer.
Another problem with conventional arrangements is that although during assembly the correct number of O-ring seals may be used, it is possible that two O-ring seals having slightly different sizes or tolerances may be inadvertently swapped.
It will be apparent that assembly of a mass spectrometer wherein one or more O-ring seals are either missing or located in the wrong position can be particularly problematic and may require extensive disassembly and reassembly of the mass spectrometer which is both time consuming and a skilled operation.
GB-2471520 (Syms) discloses an electrospray ionisation source that is attached to a mounting by a planar gasket. An input channel for a stream of nebuliser gas and a socket for mounting a liquid carrying capillary is provided in the gasket. The planar gasket disclosed in GB-2471520 (Syms) may suffer from leaks, especially in the areas surrounding the input channel. This will be particularly true if a high pressure gas is passed through the input channel. Leaks may occur, for example, if the ionisation source and mounting move apart from one another. Furthermore, if the ionisation source and/or mounting were to move laterally relative to the gasket or to one another then the stream of nebuliser gas would be inhibited. This would not only impact the operation of the ionisation source but would also promote leaks due to a potential build up of pressure.
It is desired to provide an improved mass spectrometer.